Cushion sealing device for surface effect machines



April 14, 1970 M. J. FAURE CUSHION SEALING DEVICE FOR SURFACE EFFECT MACHINES- Filed June 17. 1968 United States Patent Int. Cl. Bsov 1/06, 1/16 U.S. Cl. 180116 Claims ABSTRACT OF THE DISCLOSURE In a ground effect machine movable along a surface against which a pressure fluid cushion is formed, a plenum chamber structure for said cushion comprising a rigid enclosure borne by the machine and extending generally opposite said surface at a hover-height spacing therefrom, said end closure flaring towards said surface with said hover-height decreasing from the inside outwardly and being at a minimum at the periphery of said end closure, and a yieldable skirt extending outwardly from said periphery and flaring towards said surface at a spacing therefrom which decreases from said periphery to a skirt portion closest to said surface and defining therewith a daylight clearance, whereby said plenum chamber structure forms, in cross-sectional outline, with said surface, a convergent passage with an upstream hard wall section and a downstream flexible wall section.

This is a continuation-in-part of my co-pending application Ser. No. 498,258, filed Oct. 20, 1965 and since abandoned.

' The present invention relates to plenum chamber cushion systems for surface effect machines and more particularly tracked air cushion vehicles.

One of the objects of this invention is to design such a plenum chamber so as to obtain an even distribution of the static pressure gradient over the whole extension of the bearing surface. This is attained by giving to the Wall structure of said plenum chamber a shape which flares towards said surface from the inside outwardly.

A further object of the present invention is to provide said flaring wall structure with an inner flaring hard wall and an outer flaring flexible wall which extends the former.

Other objects and advantages of the invention will appear in the following description given with reference to the accompanying drawings in which: 7

FIGURE 1 is a diagrammatic longitudinal section of a plenum chamber cushion system according to the invention;

FIGURE 2 is a corresponding bottom plan view.

The plenum chamber cushion system illustrated in the drawings comprises a hard structure 1 which may be embodied in the platform of the ground effect machine and which forms a rigid end closure 1a for the cushion space 2, a fan 3 being provided for sup lying cushion air. This rigid end closure has an outline which converges outwardly toward the bearing surface 4 as clearly shown in FIGURE 1, so that its hover-height spacing from said surface gradually decreases from the center to the periphery 1b where it is at a minimum.

Along this periphery 1b, a skirt 8 of flexible fluidtight material is fitted and this skirt also has an outline which converges outwardly toward the surface 4, as illustrated again in FIGURE 1, so that its spacing from said sur- "ice face also decreases from the end closure priphery 1b to a free edge 8a which is closest to surface 4 and defines therewith a daylight clearance 5. Alternatively the skirt 8 may end with a turned-up edge beyond the daylight clearance 5.

Therefore, the boundary wall of the plenum chamber, opposite the bearing surface 4, has in the outline a shape which converges towards said surface from the center outwards right to the skirt end 8a, with a central or upstream section 1a of hard material and a peripheral or downstream section 8 of flexible material, these sections being joined at a cuspidal edge 1b and having curved convex faces opposite surface 4.

This flared shape provides a zone of gradually varying static pressure which extends over the whole radial stretch of cushion 2, thereby improving transverse stability of the machine.

Because of its outwardly flared shape, yieldable skirt 8 will be urged away from surface 4 by the cushion pressure which is exerted on the skirt. The tendency may be counteracted by means of springs 9 and oscillations may be damped by means of dampers 11. Of course, resilience and damping may result from the very material of the skirt, in which case external means such as 9 and 11 may be done away with.

I claim:

1. In a surface effect machine movable along a surface against which a pressure fluid cushion is formed, a plenum chamber cushion system comprising a rapid end closure formed of a hard structure extending generally opposite said surface at a hover-height spacing therefrom and flaring outwardly towards said surface with said hover-height decreasing from the inside outwardly towards the periphery of said hard structure, and a yieldable skirt flaring outwardly from said periphery towards said suface at a spacing therefrom which decreases from said periphery to a minimum at which said skirt defines with said surface a daylight clearance, whereby said plenum chamber cushion system forms, in cross-sectional outline, with said surface, a convergent passage with a central hard wall section and a peripheral flexible wall section.

2. Cushion system as claimed in claim 1, wherein said peripheral wall section has, in outline, a curved convex face opposite said surface and joined to said central wall section at a cuspidal edge.

3. Cushion system as claimed in claim 1, wherein said hard structure and said yieldable skirt are both substantially of revolution shape and define with said surface an annular passage which narrows down outwardly to ward said daylight clearance.

4. Cushion system as claimed in claim 1, further comprising resilient return means for urging said skirt toward said surface against cushion pressure exerted on said skirt.

'5. Cushion system as claimed in claim 4, further comprising oscillation damping means associated with said reslient return means.

References Cited UNITED STATES PATENTS 3,244,244 4/1966 Cockerell 128 3,267,882 8/1966 Rapson et al. 180124 X 3,275,270 9/1966 Earl et a1 180ll6 X A. HARRY LEVY, Primary Examiner U.S. Cl. X.R. 180127 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,506,084

Marc Henri Jean Faure It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 29, "rapid" should read rigid Signed and sealed this 12th day of January 1971.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer April 14, 1970 

